As Boston's mayoral race heads into the home stretch, two unions with a history of political engagement -- the International Brotherhood of Electrical Workers (IBEW) and the Boston Teachers Union (BTU) -- last week established super PACs, presumably to influence voters in the November 2 final election.

Local 103, the IBEW Boston chapter, endorsed Essaibi George's last month.

The BTU, however, has not endorsed a mayoral candidate. Establishing a super PAC could suggest they are preparing to. The union could also spend in support of their endorsed city council candidates, or remain neutral in the mayor's race, but produce ads designed to educate the public about issues of core concern to the BTU.

Super PACs (political action committees), or independent expenditure political action committees, are legally allowed to spend without limit to support or oppose a candidate, as long as the PACs do not coordinate with any campaigns.

BTU president Jessica Tang was not available for comment Monday.

Maritza Agrait, a Milton resident who chairs the new BTU super PAC, declined to disclose whether the group might support a mayoral candidate.

"Bottom line is neither candidate is endorsed," said Agrait in a text message.

The new super PACs come as Essaibi George lags slightly behind her opponent, Michelle Wu, in campaign cash on hand.

Essaibi George was also criticized last month after reporting showed one of two super PACs supporting her was found to have connections to a GOP financial consulting firm which served as treasurer for former president Donald Trump's 2016 campaign and two Trump fundraising committees.

Essaibi George later indicated she wants outside groups to stay out of the Boston mayor’s race, a point Lou Antonellis, business manager for Local 103 IBEW said is moot.

"What the campaign wants is one thing," he told GBH News Monday. "We're not working with her campaign, so we're just doing our own thing."

Antonellis added that the union took similar steps to support Rep. Ayanna Pressley and former Rep. Joe Kennedy III in their most recent races despite public declarations against accepting outside money from each campaign.

"We want to support candidates that support labor and Local 103," Antonellis said.

During Boston’s most recent open mayoral race of 2013, outside groups spent about $3.8 million to support the two finalists Marty J. Walsh and John Connolly, according to records from the state campaign finance oversight office.

Meanwhile, recent filings show the Environmental League of Massachusetts Action Fund super PAC, which supports Wu, spent $31,500 last week on supportive social media ads. The Boston Turnout Project, another Wu-supporting super PAC, also shelled out $40,000 last week on digital and cable advertising in support of Wu.